What are Library of Congress Call Numbers?

Penrose Library organizes books using Library of Congress call numbers. Similar to the Dewey Decimal classification, Library of Congress call numbers act as a book's address on the shelf. Call numbers are made up of a combination of letters and numbers that represent specific subjects. Library of Congress uses the letters of the alphabet to represent broad subject categories and subdivisions. For example, J represents Political Science and R represents Medicine.

When you find a book you're interested in the catalog, you'll see a location and call number listed. Using Make Your Home Among Strangers by Jennine Capo Crucet as an example, the catalog lists the call number as PS 3603 .R83 M35 2016. Additionally it indicates the book is shelved on the 2nd Floor and is available for check out.

To understand the call number for this book, here's how to break it down:

P represents the broad subject of Language & Literatures. Books are shelved first by this section of the call number, in alphabetical order.

PS gathers books representing American Literature.

3603 represents a further refinement of the subject. In this case it stands for books published after 2000 and is treated as a whole number.

.R83 represents the author's name. Because there are so many American authors, this number may get quite complex. This is a decimal number (not a whole number.) For example, .E485 will come after .E4 and before .E5.

M35 the final element, represents the title of the book. This is typically a whole number.

2016 is the year the book was published. Dates do not always appear as part of a call number.

On the Penrose Library shelves, Make Your Home Among Strangers is surrounded by books with these call numbers:

PS3603 .R685 C67 2005

PS3603 .R83 M35 2016

PS3603 .R893 A6 2016

To help you find where a book is located, call number ranges appear on the end panel of each row of shelves. PS3603 .R83 M35 2016 will be in the range of shelving that is labeled PS3573.A4795 M 29 1994 - PS3612.I877 S43 2006.

The catalog provides the ability to text message the call number to a personal cell phone. Standard text-messaging fees may apply.

Locations of Library Materials

Allen Room - 2nd Floor

Archives/Special Collections - 1st Floor

Atlases - 1st and 2nd Floor

Audio books - (accessible online)

Documents - 1st and 2nd Floor

eBooks - (accessible online)

General Collection - 1st, 2nd, 3rd, and 4th Floor

Juvenile - 1st Floor

Microforms - in Archives/Special Collections - 1st floor

Northwest Collection - 1st Floor

Oversize/Folio - 1st Floor

Popular Literature - 2nd Floor

Reference - 2nd Floor

Reserves - Circulation desk

Serials - 1st Floor (some accessible online)

Video - 2nd Floor

We Can Help

Don't hesitate to ask for help if you find Library of Congress call numbers confusing. Any member of the library staff or a librarian would be glad to assist you.